CODE >R
    HL POPqq, chkPS,
    17 BCALL, ( 17 == pushRS )
;CODE
CODE 2>R
    DE POPqq, HL POPqq, chkPS,
    17 BCALL, ( 17 == pushRS ) EXDEHL, 17 BCALL,
;CODE
CODE R>
    20 BCALL, ( 20 == popRS )
    HL PUSHqq,
;CODE
CODE 2R>
    20 BCALL, ( 20 == popRS ) EXDEHL, 20 BCALL,
    HL PUSHqq, DE PUSHqq,
;CODE